Creating files

Now that we understand about file naming, we are actually ready to start…creating some files and there are three main ways to create files in Unix.…The first is using a text editor and Unix has its own text editor.…We are not going to be using the text editors that you have on your Mac like…Microsoft Word or whatever it might be.…We are going to be using Unix's text editors and we are going to see how to do…that in the next movie.…There is also a technique where we can direct output from a command and put that…in a file and we will see that in a future chapter.…Then there is the simplest of all, the one that we are going to look at right…now, which is just touch.…

Let's go back to our command line and see how the touch command works.…Back in my home directory, we can just see what's in there right now, ls -la.…We will see the full list. Before we do touch, let's take a look at what touch actually does.…Let's look in the manual for touch.…Change file access and modification times.…Well that doesn't sound like it has anything to do with creating files.…

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4/29/2011

Unix for Mac OS X Users unlocks the powerful capabilities of Unix that underlie Mac OS X, teaching how to use command-line syntax to perform common tasks such as file management, data entry, and text manipulation. The course teaches Unix from the ground up, starting with the basics of the command line and graduating to powerful, advanced tools like grep, sed, and xargs. The course shows how to enter commands in Terminal to create, move, copy, and delete files and folders; change file ownership and permissions; view and stop command and application processes; find and edit data within files; and use command-line shortcuts to speed up workflow. Exercise files accompany the course.

Topics include:

Moving around the file system

Creating and reading files

Copying, moving, renaming, and deleting files and directories

Creating hard links and symbolic links

Understanding user identity, file ownership, and sudo

Setting file permissions with alpha and octal notation

Changing the PATH variable

Using the command history

Directing input and output

Configuring the Unix working environment

Searching and replacing using grep and regular expressions

Manipulating text with tr, sed, and cut

Integrating with the Finder, Spotlight, and AppleScript

Skill Level Beginner

6h 35m

Duration

2,077,119

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Q: The exercise files for the following movies appear to be broken:
07_02_files
07_03_files
07_04_files
07_05_files
08_03_files

Is there something wrong with them?

These exercises include one or more "dot files", whose file names start with a period. These files are normally hidden from view by the Finder. So that they would show up in the Finder, the period has been removed from the file names. Additionally, "_example" has been added at the end of the file name to make it clear that the file will not work as-is.
To make the dot files usable, either:

1) Open the file in a text editor to view its contents. Note that it may not be possible to double-click the file to open it because there is no file extension (such as .txt).
2) Resave the file under a new name (usually by choosing File > Save As), adding a "." to the beginning of the file name and removing "_example" from the end.

OR

1) Copy and rename the file from the Unix command line using the techniques discussed in this course. Rename the file by adding a "." to the start and removing "_example" from the end. Include the "-i" option to prevent overwriting an existing file unexpectedly.
Example: cp -i ~/Desktop/Exercise\ Files/Chapter_07/07_02_files/bashrc_example ~/.bashrc

The instructor uses the UNIX program 'units' to convert 72° Fahrenheit to degrees Celsius. The returned value of 40 is incorrect. The correct result should be 22°C. What's the reason for this discrepancy?

The problem is that units does the 5/9 calculation but does not have the ability to subtract 32. So you'll need to subtract (or add) the 32 degrees yourself.